A Robust Flexible Electrochemical Gas Sensor Using Room Temperature Ionic Liquid

Abstract

This paper introduces a robust electrochemical gas sensor featuring room temperature ionic liquid (RTIL) as electrolyte and porous polytetrafluoroethylene as a flexible substrate. Using a planar-electrodes-on-permeable-membrane structure, a flexible RTIL sensor with 9.6 mm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> sensing area is microfabricated. The sensor's response to oxygen is measured, achieving sensitivity of 0.48 μA/%O <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> , a linearity of 0.997 R <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> in range of 0%-21% O <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> , and limit of detection of 0.08% O <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> . The reported sensor structure and fabrication process enable realization of sensor arrays for multi-gas monitoring in a low power, miniaturized, and wearable system platform.